Need some technical help with fueling/running issue.

[vanmansam]

Hello all. '89 festiva, automatic with 160,000 miles. Bought a month ago.
My car stumbles and acts like its fuel starving with anything less than half a tank of gas, the engine cuts out and comes back on/jerks ect under acceleration. I replaced the fuel pump (previous owner had put in a junkyard pump) and fuel filter. The filter that was on the car was very dirty and a lot of crud and junk came out so I assumed that was my problem there, but with the new filter I still encountered the problem with about 4.7 gallons left in the tank. My spark plugs are all an even tan color and compression is okay. No engine codes thrown and I am getting around 27-30mpg which is normal for auto, so i feel like the ignition and fuel injections systems are okay.

What is my next course of action in solving my running issue? Its a pain to have to fill up every 150 miles.
I would check fuel pressure but I dont have a gage at the moment..

[Damkid]

Repair help questions belong in the repair help section.....

[drddan]

Try this thread ... the run out of gas at half tank thread

http://www.fordfestiva.com/forums/sh...ight=half+tank

[harpon]

Maybe the problem is with the fuel strainer in the sending unit located under the back seat-

use the search engine here to search for threads about replacing/ overhauling the fuel sending unit-

the unit has a strainer that's like an early inline fuel filter-

you can get the strainer cheap- several dollars, or the whole sending unit new for about 20 I think- search ebay

Be careful if you open up the top of the tank-very flammable!

[vanmansam]

Thank you for the advice guys. I have a new strainer, I will pull the pump again and put the new one on to see if that helps.

Sorry Damkid. Maybe a mod can move this? I understand that I have basically no post count am not an active member and I must look like a total noob asking a question like this especially in the general section, but frankly the general section of most niche car forums has the highest amount of traffic and I will maximize responses by posting there. Wont do it again

[vanmansam]

Okay I have researched this topic to death and think I have found a potential solution. Apparently there is an equalizing hole at the bottom of the in tank baffle. The hole is there in order to keep the level of fuel equal inside baffle as it is in the rest of the tank. The top of the baffle is supposedly at the 4.5 gallon mark, at approx the same level that I have problems. I guess that the holes at the bottom of the baffle get plugged after 20 years with garbage/fuel, and the only way the baffle can fill is by fuel spilling over the top edges; bellow 1/2 a tank the area inside the pump baffles goes dry. I got a new pump "sock" aka strainer the other day, so I will drive until I experience problems and then pull the pump and sender to check inside the tank again to to see if the level inside the baffle is low. If it is I know I have found my problem and I will clean out the baffle's holes. Will check back into this thread when I do so and post up some pictures so others know wtf I am talking about